Facebook Intro for B2B Marketers

Audience Types

Facebook has three primary audience types:
  • Saved Audiences
  • Custom Audiences
  • Lookalike Audiences
In this article, we'll explain the pros and cons of each common use case.

Facebook Saved Audiences

Saved Audiences are the audiences you can define by choosing people’s interests, location, age, gender, used devices, income level, etc.
You can create Saved Audiences both in the campaign setup phase or in the Audience Manager.
Prior to Cambridge Analytica, Facebook allowed for fairly granular demographic targeting, including the ability to target by position or role.
However, it's now quite challenging to create tightly targeted B2B audiences using Facebook's built-in interest and demographic features.
That's not to say they can't work. Interests are one of the best (and easiest) Facebook ad targeting options as they allow you to target people specifically interested in a subject related to your product straight from the Facebook UI.
You just have to closely monitor lead quality and spend to answer the question - "Am I getting high enough quality leads for a reasonable CPA?"
Unlike precise Interests, Behaviors allow you to target people by purchase history, events they like, personal anniversaries, etc. This data is gathered by Facebook; they analyze many factors and also use external data sets.
They are not always useful, but when they are, they work great! As an example, you can target people currently traveling or planning their next trip. This is priceless if you’re in the hotel or event booking market. Check them out and see if they can work for your business.
Pro: It's easy to use facebook's built-in capabilities to quickly set up campaigns
Con: Facebooks interests and behaviors are consumer focused and they have little accurate B2B data

Facebook Custom Audiences

Facebook Custom Audiences are probably the most high-value target audiences. These custom audiences allow you to re-target past website visitors and engage people who have pre-qualified interest in your product. There are multiple ways to create a Custom Audience, and we’re going to cover each of them briefly.

Creating Custom Audiences

Creating Customer Audience from Files

This first type of Facebook Custom Audience is based on your existing lists of customers and leads – the lists of email accounts, phone numbers, userIDs, mobile advertiser IDs, etc. The "Customer File" audience is a great way to target your contacts, leads, or users.
Your customer files can include 15 different identifiers, the most important ones for a high match rate being:
  • Personal email
  • Mobile phone number
  • Mobile advertiser ID
If you don't have the above identifiers, Primer is here to help! By tapping into our data providers, Primer appends those identifiers (AKA ad network matching data) boosting the likelihood that Facebook can match those individuals and serve ads to the people in your list.
Pro: You can target and serve ads to exactly who you want, preventing you from wasting ads on irrelevant people. You can also be more personalized in your ad copy/creative and significantly boost qualified conversion rates from Facebook.
Con: If you only have work emails in your list, match rates are typically 10-20%. Work email is not a good identifier.

Creating Custom Audiences Based on Website Traffic

Website traffic-based Facebook audiences allow you to create remarketing campaigns for people who have engaged with your website. These are high-value audiences as the users seeing your ads have already shown some interest in them.
To create audiences based on your website traffic, you first need to install the Facebook Pixel. See the Pixel setup instructions by Facebook. Once you’ve installed Facebook Pixel, you can simply go to the Audience Manager and create a Custom Audience based on past website traffic.
You can choose between multiple options:
  • Target everyone who visited your website
  • Target people who visited specific web pages
  • Target people who visited specific web pages but not others
  • Target people who haven’t visited your website for a certain amount of time
  • Other custom combinations
Pro: You're serving ads to people who likely have interest in your product or category since they've already been to your website.
Con: The user has to visit your website before you can serve ads to them. While targeting based on a specific page can be helpful, creating audiences that are specific to a segment (i.e. industry, role, etc.) is still not possible.

Creating Custom Audiences Based on Engagement

The latest addition to Custom Audiences is the possibility to target people who have done one of the following:
  • Visited your Facebook Page
  • Engaged with your Facebook Page posts or ads
  • Clicked on any call-to-action buttons
  • Sent a message to your Page
  • Saved your Page or posts
Pro: These people have engaged with you in the past so they're likely to do so again in the future — they're interested.
Con: These users may or may not have a purchase intent. Just because they liked your post, doesn't mean they're going to buy your product.

Facebook Lookalike Audiences

Facebook Lookalike Audiences let you reach people who are similar to your existing custom audiences (e.g. lists or re-targeting audiences) making them highly likely to convert as well.
To create a Lookalike Audience, you first need to create a Custom Audience to tell Facebook what type of users you want to reach. Next, select the “Lookalike Audience” from the audience creation menu and select a target country and a percentage (1%-10%) of the targeted country’s Facebook users. The percentage signifies the people most similar to your selected Custom Audience.
Lookalike Audiences help you to extend your ad campaign’s reach so that you only target people who are likely to be interested in your offer.
They work particularly well when they are built off of a list-based audience or re-targeting audience.

Facebook Minimum Audience Size

What's the smallest audience size possible on Facebook?

  • The short answer is 100 to load an audience, but more to actually get impressions.
    • This minimum requirement is meant to protect the privacy of the audience members, reducing the likelihood of identifying individuals via Facebook pixels or their actions on ads. There have been instances of Facebook denying the use of audiences that were well over 100 but less than 1,000, so it’s always safe to shoot for a larger audience wherever possible. If you can’t reach 1,000, use the Audiences module, to see your list of audiences and their “Availability” for use in ad sets. So long as you see the status of "Ready," these audiences are still good to go! The actual audience size (aka reach) will be revealed when you launch the audience in an ad campaign.
  • Size matters.
    • While 100 is the minimum number of people in a custom audience who can be served your ad, it's important to recognize that any list you import should be much bigger than this for a variety of reasons that we touch on below.
First, it’s important to understand how audiences work.
The most common data sources of custom audiences for Facebook Ads are:
  • Website visitors - data collected by a Facebook Pixel
  • Loaded lists - data of individual contacts or leads with some ad network matching identifiers (e.g. phone numbers, email addresses, etc.)
Facebook then cross-references that imported information with their user database to match Facebook users to the imported data. The end result is a custom audience of Facebook users that can be served ads directly, and this audience must total at least 100 users. Ergo, some of the contacts in your initial list will not be linked to a Facebook account, so uploading, for example, 100 phone numbers alone will not be enough.
And if you have not realized it yet, Facebook’s ad delivery system works as an auction system. When creating an audience and launching it in a campaign you are competing against other advertisers for eyeballs. If you provide Facebook with too small an audience, you won't have enough potential inventory to consistently win your bids or provide Facebook with enough data to optimize the user experience.
Facebook likes an overabundance of data. It provides an advantage for their algorithm, which identifies those users most likely to act in accordance with your Campaign Objective.
As an added benefit, their algorithm is then able to use your custom audience to create a Lookalike Audience of potential new customers with similar interests. The effectiveness of this Lookalike Audience depends solely on the amount of data it can use as a reference. For example, say you have a list of customers that have purchased your bird feeders. Facebook can use that list to identify potential customers who would also purchase bird feeders. Providing a large list of 5,000 customers with varied interests & behaviors would result in a much more effective Lookalike Audience than one of only 100.
So what are the real minimums?
From extensive testing (that we continue to do on a regular basis), we have found the following:
  • Awareness building for outbound >5K size
  • Direct-response, last click conversion >30K size
  • Lookalike >500

Facebook Audience Size and Match Rate

Note: If an audience was synced or loaded less than 72 hours ago the list can still be populating, as it sometimes needs 72 hours for Facebook to fully update size.
Oftentimes, audience size information is withheld by Facebook for certain audience types. You may find your Custom Audiences show an alert that it’s "Not available" or "Below <1,000". This means that Facebook is not allowing you to see the actual audience size for privacy reasons.
As long as you see the status of "Ready" these audiences are still good to go!
Read on to see why they obfuscate audience size.


In March of 2018, Facebook removed the ability to view custom audience sizes. This was in response to a vulnerability that could be potentially exploited, allowing an advertiser to identify individual user data:
A research team from Northeastern University found an exploit in which it could infer attributes of an individual included in an uploaded Custom Audience list of emails, addresses or other personally identifiable information (PII) using the estimated reach reporting available in the advertising interface:
“It turns out there is a rounding threshold in those estimates. Once that’s identified, an advertiser could potentially upload a list of emails right on the rounding threshold, for example, and then add one email (or “victim”) to the list. If the reach estimates change when a targeting attribute is selected, the advertiser can infer that person has that attribute. And vice versa, if it doesn’t change, then it can be inferred the person does not have that attribute.”
The official Facebook response (via a post on the Bug Bounty program page) stated that custom audience size data would simply no longer be available. The issue also made it into the platform status tool, and it appeared this would be the new normal.
While not directly related, Facebook’s issue with the log-in information of almost 50 million accounts may lead to increased scrutiny of user data.
Based on these challenges, it may seem safe to assume that advertisers will have limited access to custom audience data.

What this means for Audience Size

If inconsistency in the display of custom audience data is any indication, Facebook is still working through these issues. Given the high public scrutiny of any potential privacy irregularities, it’s unlikely we’ll see the wide availability of deep data for custom audiences anytime soon.
It is possible that you won’t see the size of the audience anymore or smaller size will be reported, regardless of the fact that they are ready and that reach will exceed the stated audience size.

What happens with your ads?

Everything will work fine, and ads delivery and reporting will remain unaffected by this change. You will still be able to create Custom Audiences, as well as ads using any type of Custom Audiences on Facebook. It’s only the reach estimate that’s missing.
Conclusion: Measure results through the actual reach of your campaigns vs. the stated audience size in Facebook's Audience Manager.